1. Field of the Invention
This invention relates to a differential gear device for a vehicle and more particularly to a differential gear device with a limited slip differential device.
2. Description of the Prior Art
Conventional differential gear devices for a vehicle, for example as disclosed in Japanese Laid Open Patent Publication No. 63-195449 (U.S. Pat. No. 4,781,078), includes a device with a planetary gearing. The planetary gearing is generally provided with a sun gear for engaging planet gears which rotate and revolve on the sun gear and a ring gear for engaging the planet gears and rotating around the planet gears. The planet gears are respectively supported by a planet carrier. Driving force from an engine is input to the ring gear, and the planet carrier or the sun gear outputs the driving force to the right axle or to the left axle.
In this configuration, when a difference in the rate of rotation occurs between the right and left axles, this difference is absorbed by the planetary gearing and the driving force can be properly output to the right and left axles. As a result, when turning a corner, even when a difference in the rate of rotation occurs between the right and left axles, a smooth drive is possible.
However, when a wheel on one side encounters snow, ice or mud and spins, the driving force is spent on the spinning wheel and the vehicle cannot move. Therefore, limited slip differential devices (LSD) for limiting the difference in rotation has been developed. The device of the above Patent uses a multiple disc clutch as a device for limiting the differential motion.